In order to prevent danger to assembly and/or maintenance personnel, the optical communication cable held on the phase cable of a high-voltage aerial line by an adhesive strip must be led in a voltage-free fashion, i.e., at ground potential, to the cable fitting fastened to the tower. The decoupling from the high-voltage of the phase cable is standardly accomplished by an insulator positioned before the cable fitting, through which the ADL (All Dielectric Lash) cable, as it is called, is routed. Corresponding insulators are known from EP 0 303 740 A1 and from DE 196 48 755 A1. However, these insulators cannot be retrofitted onto already-laid ADL cables.
In DE 32 42 008 A1, a suspension device is specified that is used for the guiding of, in particular, light waveguide cables. This device comprises a guide part for guiding the light waveguide cable, which part is fastened to a tower for the high-voltage line. At both sides of the guide part, the suspension device is provided with a respective insulating element. The respective insulating element can be made up of a multiplicity of individual elements that can be put together.
The subject matter of the invention is an insulator with which, in particular, an already-laid ADL cable can be guided and can be decoupled from the high voltage of the phase cable, and/or with which a disconnecting switch can easily be jumped or bypassed. This object is achieved according to the invention by an insulator comprising two parts, which can be assembled around the cable, each part has a half-pipe and an insulator element that is connected to the half-pipe.
The proposed insulator contains two half-pipes or half-shells having sufficient transverse and longitudinal stability, and preferably made of glass-fiber-reinforced plastic (GFK), as well as an insulator element that surrounds the half-pipes at least partially and is made of silicone. In order to enable the individual components to be joined and held in this position more easily, the half-pipes and the insulator element are respectively equipped with guide pins or, respectively, guide openings or bored guide holes, situated opposite each other.
In one of the half-pipes, a GFK rod protruding from the half-pipe can be glued in, whereby the GFK rod and the ADL cable to be guided through preferably have the same diameter.
At least one of the half-pipes comprises, outside the region covered by the insulator element, bored filling holes and bored ventilation holes, in order to enable the hollow space formed by the joined halves to be filled with a high-voltage-stable or electrically insulating material, preferably an epoxy resin (e.g., Protolin), or, respectively, to allow the air displaced by the filling compound to escape.
After the two insulator halves have been joined, a slit or slotted sleeve, preferably made of GFK, is pushed onto each of the two cylindrical insulator ends and is glued to the half-pipes.
In the assembly of the insulator, a twin-chamber sack containing a sufficient quantity of a two-component silicone resin (preferably LSRxe2x80x94Liquid Silicone Rubber) is preferably used. After the two components have been mixed, the silicone resin is applied to the edge surfaces of the silicone insulator halves, and the insulator halves are placed together and are heated to approximately 100xc2x0 C. for approximately five minutes, and are thereby adhesively bonded to each other. Subsequently, the epoxy casting resin, which is used as a filling compound, preferably Protolin 51, is brought, via the bored filling holes, into the hollow body, which is sealed at its end side by means of two silicone stoppers. This resin fuses with the ADL cable(s) fixed in the respective half-pipe by a plastic compound (e.g., Prestik), with the GFK rod glued into one of the half-pipes, and with the insulator halves, to form a unit having tensile strength.
The insulator without GFK rod, placed on supports or hanging on the line or phase cable, can jumper the tower or a disconnected switch.